"Ching, look out for--oh, wait, ha, ha! I forgot to warn him OUT LOUD. Pity. Still, he's getting the crap beat out of him. Why, it's like he can't even see the guy! Oh, wait... that's right...!"

As entertaining as it is to watch a violent homeless person bitch-slap Diana and Ching around, it's even more entertaining when you realize that that crazy, violent homeless person is, of course....J'onn J'onnz, the Martian Manhunter

I think someone needs a cookie.

Yes! Godlike alien J'onn having a freakout and beating the tar out of a powerless dress shop owner and a tiny old blind guy. That's what comics are all about.

"This is it; I am never letting Ching pick out my outfit again!"And, for the record, Diana; J'onn will NEVER regain his balance.

Oh, wait, there's only one more thing that will make this incident perfect:

Faceplanting Batman. "But... but I'm the goddaMMFFFPHHH!"

Eat sawdust, stupid Bronze Age Batman.

Wild man. Mad dog. J'onn J'onnz is insane, people.

Oh, but don't believe me; believe HIM.

That wasn't "something in your mind", JJ; it was your mind. How snapped is JJ? Let's just say that if his daughter is running for Homecoming Queen, pull your daughter out of the contest immediately.

So someone gives JJ a cookie to calm him down, and, while Diana and Ching are having their bones reset, he calmly reveals that, "oh by the way, I've been lying to you about my backstory since I was introduced 15 years ago. I am essentially an escaped war criminal, and the Martian equivalent of Robert E. Lee."

That retcon is breezier than J'onn's Martian-breath. Still, the JLA is long since accustomed to rolling with whatever ridiculousness JJ spouts, since he's:

(A) powerful enough to kick any of their asses and(B) crazy as a loon.

Therefore they do not say, "What do you mean there's a planet-threatening war going on on Mars the entire time we've been working with you, during which we've jaunted off to about 30 different alien worlds and could have stopped off on Mars to lend a hand at any point, particularly since that war might threaten Earth? And why did you just beat the crap out of an old blind guy at a carnival? ARE YOU INSANE?" Because they already know the answer to that question.

So instead they say, "Um, okay, J'onn sure. That sounds great; nice to know. Need a lift somewhere? Or will you just be wishing yourself into the cornfield now?"

There's never really any explanation why he's at the carnival, or dressed like the Invisible Man (particularly since he's a shapeshifter who can turn invisible), or freaks out violently just because there's a fire-eater there (dude; just walk away and get an ice cream cone, or better yet, just create one with your mind). But it's the Martian Manhunter, after all; if you are looking for sensible or even comprehensible explanations of his behavior then you've missed the point of the character.

Turns out that one of J'onn's previously unmentioned godlike powers is the ability to violate the Fourth Wall with his mind and telepathically influence comic book writers and editors, because they obligingly backed up J'onn's crazy story by retconning all of Mars to fit his babblings.

Suddenly there were two 'races" on Mars, the white and green, who'd been engaging in a long race war and J'onn had been exiled to the Martian desert wastelands by his enemy, Commander Blanx, for 13 years.

In a hilarious send-up of The Lorax, Blanx basically sells off Mars to be strip-mined. In essence, Mars is the West Virginia of the solar system.

Denny O'Neil was fond of writing stories that contained veiled social commentary. If by 'veiled' one means "festooned in neon tubing, sparklers, and 'THIS IS OUR MESSAGE, STUPID!' arrows". This is one of the more subtle ones.

So JJ and the Leaguers go clobber B'illy Blanx's little mob of white Martians, but don't manage to stop him before he burns off everything on Mars including the atmosphere. A few Martians escape in a starship for parts unknown while J'onn, the perennially calm stable center of the JLA, beats Blanx to death with a Mars globe.Yes, really.

Oh, and somewhere during all that, Hal falls asleep.

Yeah, well, staying up till 5AM with three Pan-Am girls will do that to you, Hal.

Unfortunately, Superman catches Hal right before he lands, or I'd be sharing with you a picture of Hal getting hit in the head WITH MARS. Which would be impressive, even for Hal, particularly if, unlike Blanx, he survived getting hit in the head with Mars. Oh, how many licks does it take to get to the center of Hal Jordan's noggin? The world may never know.

The upshot of all of this is J'onn leaves Earth to search the stars for the S.S. Martian Minnow and the JLA lets him because he's

(A) powerful enough to kick any of their asses and(B) crazy as a loon.

Don't let the door hit you on the way out, er, I mean, "godspeed!"

So, the Manhunter is put on a bus and Earth-2 rejects Red Tornado and Black Canary are sniffing around the campfire, begging for scraps of readership. What other disaster could befall the Silver Age Justice League?

"blue flame"..."the only source of heat on Mars, the only FIRE we knew"

So all this time (or rather all THAT time, because it was later changed again) J'onn was afraid of the very thing that the Martians had fought over. Their survival depended on that which could destroy them. Huh.